Notice Regarding the Opening Ceremony of the Ono Plant

IBIDEN Co., Ltd. (Head Office: Ogaki City, Gifu Prefecture; President: Koji Kawashima) announces that it held the opening ceremony for its Ono Plant on October 10, 2025 in Ono Town, Ibi District, Gifu Prefecture. Construction work and preparations for mass production at the plant had been underway.

The Ono Plant acquired its factory site in September 2021, commenced construction in December 2022, and was completed in January 2025. As our largest domestic production area and a world-leading IC package substrate manufacturing facility, it is scheduled to sequentially begin mass production starting in October 2025, primarily for AI server products.

The opening ceremony was attended by numerous distinguished guests, including Governor Yoshihide Esaki of Gifu Prefecture, other government officials, key customers, and construction personnel. On behalf of the organizers, our President Kawashima, stated, "We sincerely appreciate everyone who contributed to the construction and the local community for their understanding and cooperation. The Ono Plant will serve as a crucial hub, significantly expanding our production capacity for AI server products. We are committed to establishing a system capable of responding swiftly and flexibly to our customers' diverse needs, contributing to the advancement of AI technology. We are deeply proud that Gifu Prefecture can support products that significantly underpin the world's AI infrastructure."

President Kawashima offering remarks

The official ribbon-cutting ceremony

The demand for cutting-edge IC package substrates, primarily for AI servers, is rapidly expanding. We aim to secure a large share of orders for high-value-added product orders by combining mass production at our Ono Plant with the flexible utilization of existing factories. Through stable product supply, we will contribute to the development of the global semiconductor industry.

Ono Plant

Overview and Features of the Ono Plant

Location	237-1 Shimoiso, Ono Town, Ibi District, Gifu Prefecture
Structure	Steel-framed, 6-story above-ground (seismic isolation structure)
Site Area	149,189 square meters
Production Items	Advanced IC Package Substrates (for AI servers and networking)
Schedule	September 2021: Basic agreement for factory site acquisition December 2022: Construction commenced April 2023: Certified under the Ministry of Economy, Trade and Industry (METI) supply assurance plan (eligible for subsidy) January 2025: Plant completion Commencement of initial operations in July-September 2025

*As of October 2025

The Ono Plant boasts one of the largest sites and production areas within our company in Japan. Certain areas within its buildings maintain a high level of cleanliness comparable to semiconductor factories, making it a world-leading IC package substrate production facility, featuring process automation and other cutting-edge technologies.

From a business continuity perspective, we have implemented robust measures to prepare for large-scale disasters. For earthquake preparedness, seismic isolation rubber pads are installed beneath the building to reduce vibrations. For flood control, the building is constructed on an elevated platform approximately 4.5 meters above ground level. The slopes around the elevated platform are designed to minimize damage for landslides. Additionally, comprehensive greening is employed to preserve the landscape and reduce environmental impact.

[Contact]
Fumiyasu Yoshikawa, Takashi Yamamoto
Public Relations & ESG Group
Strategic Corporate Planning Division
Tel: +81-584-81-2591